Separate numbers from title

I've got a lot of files with the following filenames:
15Lasgo - Surrender.mp3

Now I would like to use mp3tag to get tagnames from the filenames,
%track%%artist% - %title%

problkem is that this returns:
track: empty
artist: 015Lasgo
title: Surrender

Is there a way to separate the 15 from Lasgo within mp3tag?

sorrie guys.. already fount it.
Created a _FILENAME action
thanks anyway!